APPLICATION OF THE HYDROGENPHOSPHONATE APPROACH IN THE SYNTHESIS OF GLYCOSYL PHOSPHOSUGARS LINKED THROUGH SECONDARY HYDROXYL-GROUPS

The hydrogenphosphonate approach has been used in syntheses of methyl α-d-mannopyranoside 2-, 3-, and 4-(α-d-mannopyranosyl phosphate), benzyl β-d-galactopyranoside 2-(α-d-mannopyranosyl phosphate), and methyl β-d-galactopyranoside 4-(α-d-mannopyranosyl phosphate). Condensation of 2,3,4,6-tetra-O-benzyl- or 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl hydrogenphosphonate with suitable, partially acylated monohydroxy derivatives in the presence of Me3CCOCl, followed by oxidation of the resulting hydrogenphosphonate diesters with iodine, gave the O-protected phosphate diesters in yields of 67-87%. Deprotection then gave the glycosyl phosphosugars. © 1990.